


Part of Your World

by kelex



Category: Doctor Who
Genre: F/M, Merfolk AU
Language: English
Status: In-Progress
Published: 2015-08-28
Updated: 2015-08-31
Packaged: 2018-04-17 18:08:14
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,839
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4676288
Author URL: https://archiveofourown.org/users/kelex/pseuds/kelex
Summary: <blockquote class="userstuff">
              <p>Dr. John Smith, of the Gallifreyan Marine Institute, with companions Dr. Martha Jones and Dive Captain Jack Harkness discover a new civilization (and a little bit more) under the seas of Earth.</p>
            </blockquote>





	1. Prologue

**Author's Note:**

> Ratings and pairings will change/be added to as the series goes on. Merfolk/mermaid AU. Any characters you recognize are purely intentional. ;)

"Doctor? Doctor Smith?"

"Hmm? Oh, yes! Hello!" Dr. Smith waved at the field assistant that was coming towards him. "Sorry, I was just thinking about things."

"Oh? Like what?" 

"Ohhh, well, what the salinity of your Earth oceans are compared to the salinity of ours on Gallifrey, and if that's going to make a difference in the sea life. You've got a higher sodium content in your water than we do, and what kind of effect the salt or lack thereof is going to have a biological effect on the specimens in your ocean. And what kind of habitat the Gallifreyan species I brought are going to need. Oh, sorry, and you are?" He stuck out his hand.

"Jones, Dr. Martha Jones." She shook the Doctor's outstretched hand, and consulted the tablet she'd been carrying. "We've been analyzing the water samples you sent us last year, and we've managed to replicate everything except the living bacterium, which we've managed to transplant into the water, and it's thriving. Soon as your samples are ready, we can transfer them to the holding tank." 

"Oh, brilliant, that's brilliant!" He shoved his glasses back up his nose, and dug in his pockets for a pen and a notepad before scribbling some notes--including the new assistant's name. So he wouldn't forget it. "I also brought the deep pressure capsule, and plenty of fuel rods, and my partner on Gallifrey, Professor Yana, has set up a long-range data link, so that whatever we find on the deep floor, the data is relayed straight to Gallifrey and to Marine Command at the same time.

Martha's fingers were flying over the tablet as Dr. Smith spoke, getting down all the information that he was spewing out. The man spoke almost literally a mile a minute, and she made sure she got down his partner's name--Yana--and made a note to look up whether or not the tablet had access to the data link. "Are you sure you can broadcast from that deep?"

"Oh, sure, the TARDIS can pretty much communicate anywhere," he said proudly. 

"TARDIS?" Martha asked, confused. 

"It's the capsule. Travel And Research Device In Seascapes. Works a bit hard, I know, but that's what the Institute named it." He gave a bit of shrug. "We've been through a lot, me and the TARDIS." 

Martha waved to another man approaching the dock, and turned back to Dr. Smith. "Dr. Smith, meet Captain Harkness. Captain Jack, this is Doctor Smith. Captain Harkness is our dive team captain, and he'll be going on the… TARDIS, is it? With us."

The handsome captain stuck his hand out, and gave Martha and Dr. Smith a flirty smile. "Hello there. Captain Jack Harkness." 

"Dr. Smith, hello!" The Doctor pumped Captain Harkness' hand. "Pleased to meet you!"

"Call me Jack, please." He pushed his hair off his forehead, and looked over the shimmering ocean. "We're going all the way down, Doctor?"

"Yes, sir. Down to the bottom of the Marianas Trench. The TARDIS can withstand twice the pressure at that depth, so I don't think we'll have any trouble." He rubbed his hands together, and grinned over his shoulder at Martha. "Tell you what, let me get back to the lab, make sure everything's in place, and Captain, we'll be ready to start descending tomorrow morning, first thing. Seven?"

"Sure, I'll be there. What kind of equipment should I load? Dive suits?"

"Yeah, load in enough for all of us. I'll make sure Yana packed in the differential forcefield balancers, so we can get out of the TARDIS safely and explore if we need to."

"Torches," Martha suggested. "Loads of torches and batteries, please." 

Jack took the tablet from Martha and started making an equipment list. "Torches are already on the basic list," he added after a moment's scanning. "Want to add in some extras? We'll have to delete something, find a place to match the weight allow--"

"Oh, there's no need. The TARDIS doesn't have a maximum weight allowance." The Doctor's smile was mysterious. "You'll find out in the morning. Ta!" He waved at his new co-workers as he headed back to the lab, and left the Captain and Martha exchanging baffled glances. 

"No weight limit?" Jack asked.

"Beats me," Martha answered. "Guess we better plan for one anyway, just in case he's bragging a bit about his ship."

Jack nodded his agreement, and bent his head together with Martha as they pored over the equipment lists and made trade-offs. 

\-----

"Smith to Yana. Smith to Yana, are you there, Professor?"

"Yes, yes, I'm here, hold your impatience!" There was a burst of loud static, and Dr. Smith cringed backwards before Professor Yana's weatherbeaten countenance appeared on the screen. "What do you want?"

"Checking the data link, and scheduling a dump of our data core into the university here." 

"Don't you do that!" Yana flicked switches on the other end. "Our data can't be dumped raw into their computer system, it'll overwhelm it. You have to dump it through the filter and then the translator, so it can be changed into something the humans can read!"

"Oh, right, right, sorry. I forgot." Dr. Smith looked chastened, and he followed Professor Yana's instructions to the letter. Soon, a steady stream of data was pouring into the University data core. "There, that'll keep them busy for a while. Transplanted specimens seem to be doing fine; while Dr. Jones and I are under the surface, you'll be getting updates from the lab techs."

"Fine, fine. Chantho will be responsible for taking those reports and getting them back to me. She's been dying for a bit more responsibility and I don't want to disappoint her, dear girl." 

"You're just a soft heart, Professor." Smith sat back in his chair and laced his hands behind his head as the data stream ran. "I'll contact you tomorrow evening with the fuel consumption readings, but I'm anticipating we might need another shipment of fuel rods. I think the TARDIS is going to be spending a lot of time at the bottom of the trench."

"Oh?" Yana's face showed a sudden enthusiasm. "Have you found something? New readings?"

"No, just a feeling."

"Hmph. Well, don't get yourself into any trouble. I'll prepare another shipment of rods, and if you need them, I'll send them on the next shuttle." Yana scowled at his younger colleague. "I'd feel much more comfortable if you'd take another Gallifreyan with you. You have no idea how these humans are going to react under a stressful situation, and if something happens to you, they'll have no idea how to care for your biology. I've already alerted Mrs. Jones to your--"

"Oh, for God's sake, leave Harriet alone. She's got enough to do as University President than listen to you complain." Smith propped his feet up on the console and glared at Yana. "I'll be fine. The TARDIS can reach you if anything happens, and I've met the dive captain, Jack Harkness. Lovely man. Seems to know his stuff." 

"Hmph. Since I can see you're not listening to me, Yana out." He closed the connection, leaving Smith to stare at a black screen. 

The Doctor giggled. Professor Yana was an old man, and he usually adhered to the older ways of thinking. Smith himself was of the younger generation, and they had adopted a whole new attitude and a whole new set of rules regarding alien contact, cooperation, and off-world projects. Smith had been first to volunteer, and he had been chosen for the mission to Earth. 

Gallifrey needed help; they weren't polluted as Earth, not nearly. Nor were they as ignorant of their world as the humans were; so much of their planet was unexplored! No, Gallifrey's problem was with their population; it was growing, quickly, and even with the sky cities and glass domes, they were starting to see long-term problems. If their population continued, with 3 million children per generation and increasing, they were going to run out of resources and space in about five or six generations. So they were helping Earth and other Level 5 planets to explore their worlds in the hopes of finding areas that they would be willing to let Gallifrey colonize.

So far, the Trench was the best spot Earth had to offer. It was unexplored, untapped, and really too deep for humans to venture alone. Gallifrey had pressure domes that could cover entire cities, and they could easily populate the bottom of the sea floor, and would share with the humans whatever natural resources they needed from the ocean. 

But he wasn't going to get his hopes up. 

Instead, the Doctor set a monitor up on the data stream, set it to wake him if there were any problems or difficulties, and left the control room. He was going to go to bed, get some rest, and wake up early in the morning for a head start. 

On his way to bed, the Doctor detoured to the launch center and ran his hands over the smooth surface of the TARDIS. Right now, it was a shimmering blue color, chosen to match the water closely as possible, and the reflective surface would change to match the tones the deeper they went. "Goodnight, girl."


	2. Chapter 2 -- "The TARDIS"

**Summary for the Chapter:**

> Captain Harkness and Dr. Jones join the Doctor on the TARDIS and discover life under the sea (is better than anything they got up there!).

Captain Harkness and Dr. Jones were on the dock early the next morning. There were pallets of supplies, bags and boxes and trays and cans. And they were waiting for seven o'clock to hit so they could load the equipment onto the Doctor's vehicle, the… "What did he call it again?"

"TARDIS," Martha clarified. "Like that's even a word."

Jack checked his watch; quarter of seven. "Fifteen more minutes, and then we're calling him."

They weren't going to get the chance to; before he could check his watch again, the surface of the ocean broke. Out of the whitecaps rose--

"Is that a phone booth?" Martha blinked, several times. Square, bright blue, with what looked like glass windows, it bobbed serenely on the ocean--on top of the ocean, literally, as if it were just sitting on a street corner somewhere. 

"That's what it looks like--let's hope that's just a whimsical paint job." Jack rapped smartly on the front door, and was rewarded with the hollow thump of knuckle on wood. "What the hell, that's made out of wood!"

The doors swung open, and the Doctor was standing there in a bright orange dive suit with a yellow helmet hanging down his back. "Hello! Good morning, Jack! Martha, how are you? Ready to go?"

Jack and Martha traded surprised glances, and then looked back at the TARDIS bobbing on the waves. The box itself looked about seven by seven feet… about the size of a regular phone booth. However, the inside… "It's… it's… "

The Doctor's smile widened.

"Bigger on the inside," Jack finished, while Martha was still trying to figure out how it worked. 

"Well, yes. Gallifreyan science allows us to fold spaces in so that we can fit a huge amount of space into a small container."

"It's bigger on the inside," Martha repeated. "That's not possible, unless you can--"

"Manipulate dimensions," Jack suggested, just to prove he was more than handsome muscle. "He's talking about folding dimensions inside a container so that multidimensional portals can be accessed at once."

"Yes, if that makes you feel better, but not really," the Doctor confirmed. "Oh, that your stuff? Let's get it on board, allons-y!"

"How much coffee have you had?" Martha asked as she started pulling the wheeled suitcases that held her and Jack's suits. 

"Coffee? Not a drop, although there's a pot in the galley if you'd like some." He polished his glasses, and then sprinted over to the ramp. "Here, let me help you load that, it's going to take forever if you don't." 

Martha surrendered the wheeled cases. "Those are the high-pressure dive suits." 

"I'll take them down to the airlock, and be back to help with the rest," the Doctor promised, and disappeared down the hallway, and then literally vanished from sight as he turned a corner.

Martha met Jack at the door of the TARDIS, and looked over her shoulder as she met him. "I think I see now why he said there wasn't going to be a weight limit."

Jack just nodded his agreement. "I think this is going to be the strangest thing we've ever done."

"I think you're right about that."

\-----

Seven-thirty came and went, and it was half eight before they were ready to go. The Doctor had insisted on helping Jack and Martha try on their dive suits, just like he had, and he had helped them install the pressure-resisting forcefield generators, so that they were as protected as he was. _This'll do, keep you safe all the way down at the bottom when we get there, cause I'm going outside and I think you'll want to go, too,_ he'd said, and nobody really argued with him. 

"So this is the TARDIS," Martha said, sitting in the chair by the window. It was a nice, comfortable armchair that had appeared by the time she and Jack had gotten back up to the control room, and the control room had totally reconfigured itself. The dimly lit coral-like interior had changed into a brightly-lit ovoid room, with a curving window across the front of the pod and what felt for all the world like a submarine-type pilot console.

"Yes, yeah, this is my girl. We've been through it, me and her." He stroked the console lovingly, and Martha could've sworn she heard the console purr in response. A quick glance at Captain Harkness made it clear he'd heard the rumble, too, and had probably interpreted it the same way. "We've been all over Gallifrey's oceans, a few alien oceans too, but your Earth ocean here is the most hospitable by far."

"Hospitable?" Jack was helping navigate, after a quick tutorial by the Doctor, and he put the ship on automatic descent so he could turn to glare at the Doctor. "Hospitable?" he repeated. "High salinity, no light, and a bunch of fish that would just as soon bite you as look at you?"

"No, not really," Martha said quickly. "Most of the species that we're going to run into down here are going to look strange, but they'll likely be as afraid of us as we are of them. Several of them are poisonous, yes, because that's their defense or predation mechanism, but they're not out to target us, specifically. Sharks, for example, they're not really man-eaters. They just attack us because they're either afraid of us, or because we are doing something that represents prey behavior. And if they do bite a human, they instantly stop attacking because we don't taste good to them," she added. "We're just not part of their diet."

The Doctor flashed her a grin. "Oh, I like you, Martha Jones. Not afraid to speak up, tell us what we need to know. Good on you!" And then he paused, and looked a bit guilty, like a boy trying to hide cookies from his mother. "Ah, speaking of what you need to know. You, erm, you might find yourself understanding things like whale songs or dolphin clicks." An apologetic lift of his eyebrows. "The TARDIS has a translation circuit that picks up any attempt at communication and translates it, then beams it directly to the speech centers of your brain via a telepathic circuit. Thought I'd let you know before you heard a fish out there call you ugly." 

Martha's mind was whirling with possibilities. "You mean that this machine understands whales?"

"Yeah, any intelligent attempt at communication. Written stuff, too, but that takes a while, so if we run into any sunken ships, give it a bit and you can probably read their markings." 

"Could we borrow that? I mean, the telepathic circuit? We've been trying for decades to translate whale song and prove there's a language there!"

The Doctor laughed. "No, I can't give you the circuit, but I can lend you the TARDIS. Soon as we're done with the Trench exploration, I don't have anywhere else to go. Long as we can share the information, I don't think the University will mind if we use the TARDIS for that." He'd double-check with Professor Yana later, after this mission was done, but he didn't see a problem with it. 

"Oh, I've got to go. I've got to make some notes, and start a proposal, and--Jack, will you help me? Can I say you'd be willing to head the expedition?"

"Sure, why not? I love this ship; I'd love the chance to sail her again." Jack was grinning at Martha's enthusiasm. "But why don't you start recording now? There's a pod about eight or ten klicks off our course. I can take us close enough to get some fresh samples, and we can see how the TARDIS handles it."

"Can we, Doctor?"

The Doctor shrugged. "Long as we can get back on our same course, I'm all for it! I love an adventure! Our descent's only meant to take a few hours, and we're scheduled out for the whole day. We've got time." 

Jack spun around in the pilot's chair, saving the coordinates of their previous course while the Doctor charted the new course towards the pod of whales that Jack had found. The TARDIS made a soft groaning noise as she stopped and changed course, but pretty soon they were on track for the whales. 

Martha was bouncing in her chair. "Captain, listen! We're receiving whale song already!" It was haunting, and the TARDIS identified it as humpback. "It's a migration song, we've heard songs like this before when they've been moving in their migratory patterns," she continued.

And then everybody shut up at once as translation came through--as music, at first, but then with vocals. 

_You are friendly, are you not? You do not attack us. Are you friends to the pod? Please do not hurt us, we only wish to feed and live. Our friends are deep, they know you come, they hide until they hear our song. Please tell us, friends, if you are friends, or if you mean to hurt._

Martha's jaw was hanging open, and Jack's eyes were full of wonderment. "Oh my God, they're _intelligent,_ " he breathed. "Not just smart, but intelligent, like us. Their own language."

"Well, yeah, you didn't already suspect it?" The Doctor flipped open a communications channel. "We're friends, we're not here to hurt you. We just want to listen to you for a bit, is that all right? So we can learn more about you."

_People! You are people! We do not mind, we only wish to live and feed. If you do not mean us harm, we will not harm you._

They went back to singing, which the TARDIS translated as music again, until the voices came back.

_…the boats came, and they killed many of us. Took babies alive, and we never saw them again. But we were friendly, we were nice. We did not sink their ships. You cannot sink their ships, either. We are peaceful, we only want to feed and live. We are friendly, they like to watch us, and so we let them see that we are kind. Only our friends of the deep know our true nature, and we will protect them with our song. When we sing, we must be sure that we sing to the deep ones, so they know they are to hide. We must protect the deep ones. Once we were plentiful, once we ruled the oceans, we and our families. We were many, but then the boats came, and they killed many of us. Took babies alive…_

"Friends of the deep?" Martha asked, scribbling notes on her tablet almost as fast as the TARDIS translated. "Can we ask them about that?" 

"Rather not, we did say we only wanted to listen for a bit. This is… well, it sounds like a story, doesn't it?" the Doctor asked. "Like a mythology, almost, listen to the way they're telling it to the calves in the pod. Over and over again, like the story is something they've got to internalize." 

The Doctor, Martha, and Jack all listened, mesmerized, as the whales repeated their song over and over again. "This ought to be more than enough to get your grant, Dr. Jones," Jack said softly, unconsciously running his fingers over the control panel. "And you can be damn sure I'm gonna be right there with you when you get it."

"Serves you right," the Doctor said after a moment's musing. "You people hunted these creatures until they were nearly extinct from the universe, and now you're all surprised they're a bit gun shy and are incorporating you into their stories."

Martha and Jack exchanged a few long, dark looks at that, because neither one could deny the rightness of the Doctor's words, while at the same time, it scraped both of them the wrong way. "I guess you people on Gallifrey never did anything like that."

"Oh, no, we did. We hunted and we gathered many resources until they were nearly extinct, and then we learned better. We found out what parts they played in the ecosystem that kept us alive, and we brought them back from the brink. Engineered breeding plans, wildlife refuges, even made planet-wide changes in our economy and our way of life, and now we've got a world that's flourishing with people and plants and animals." Flourishing too much, maybe, but that was a discussion for another day. "You people know better, and you still don't care."

Martha butted in this time. "But we do care, Doctor, or we wouldn't have programs like this. Maybe we're not as advanced as you are, but we're doing the best we can. There are groups of people all around the world who advocate to save the whales, or preserve the habitat of endangered animals, but bigger groups have special interests, and--"

"No planet-wide unity," the Doctor said sagely. "You could learn a lot from planet-wide unity. Once you get everyone in the same hip pocket, then you'll all be on the same page. No more special interests, nothing like that getting in the way."

"Boy, do you have a lot to learn about Earth politics." Jack steadied the controls as the pod passed them by. "Ready to return to previous course, and should reach the descent point in twenty two minutes, give or take a few seconds." 

"Just let our friends know." The Doctor opened a channel one last time. "Thank you for letting us listen a bit! We're heading back now, hope to see you again!" He sort of waved through the front glass, and several of the whales flicked their rear fins as a sort of answer before the TARDIS bobbed around and headed back for the Trench and the Challenger descent point.


End file.
